There are many applications where it is important to quickly and reliably detect gas leaks, particularly in systems which use hazardous or flammable gases, such as hydrogen, natural gas, carbon monoxide or the like. In hydrogen fuel cell systems, for example, leaks must be detected quickly to avoid safety hazards. If the concentration of hydrogen in air exceeds about 4% there is a risk of explosion if the hydrogen is ignited.
There exist a variety of prior art systems for detecting leaks of hydrogen and other gases. For example, Bette et al. (U.S. Pat. No. 6,156,447) disclose a method of detecting a gas leak between the anode and cathode areas of a PEM fuel cell wherein the entire cell is initially purged with nitrogen and then the cathode area is filled with oxygen and the anode area is filled with hydrogen. The voltage of the cell is then monitored, which will indicate if there is a leak as the faster the cell voltage drops below a predefined limit the more likely that a leak is present in the cell.
DiMeo, Jr. et al. (U.S. Pat. Nos. 6,265,222 and 6,596,236) disclose thin film solid-state sensor arrays for detecting the presence of hydrogen and other gases.
Berthold (U.S. Pat. No. 6,519,041) discloses a fiber optic hydrogen sensor system comprising a plurality of hydrogen sensors strategically located around a system to be monitored.
There exists a need for a method and apparatus which can both detect a gas leak and determine the location of the leak quickly and efficiently.